D* Specification

D* Specification

 

We don’t use D* because it is an obsolete figure of merit which was used to compare single element detectors. It does not work well for comparing FPA type detectors. It has been replaced by NEDT by the industry because there are no assumptions or approximations in the calculations – it is an empirical, straightforward, and easy to understand measurement.  A D* calculation requires the noise bandwidth or noise spectral density, which can’t be measured and so has to be assumed or approximated.